Technical data

MESOMATIC Automation und Messtechnik GmbH D-71394 Kernen
3. The serial interface
3.1. Connection
Data is exchanged between the master computer and the DK910 (slave(s)) via a serial
interface (X2).
The data format is 8N1, with function F 53 the baud rate can be selected between 9600 and
19200 Baud.
3.2. Commands
Commands consist of an '!'=21Hex=33Dec, followed by the actual command character. When the
DK800 receives a command, it checks whether it is possible to execute it. If so, it answers
with ACK=06Hex=Ctrl-F (acknowledgement) and executes the command. If the command cannot be
executed, it answers with NAK=15Hex=Ctrl-U (negative acknowledgement).
After ACK or NAK has been sent back, the DK910 disconnects the communication.
The basic timing is as follows:
1. DK910 receives the command (or data).
2. It checks whether the command is executable.
3. It answers with a ACK- or NAK-character.
4. It starts the execution of the command.
3.2.1. Net (Taring)
Taring is carried out to the command:
!N (21Hex & 4EHex)
Reply: ACK = The DK)!0 displays the net weight.
NAK = Taring is not possible, e.g. the weigher is in motion.
Taring can be executed a number of times in sequence without the unit switching back to
"gross" mode.
3.2.2. Gross
The gross command cancels taring (net weight display). The command is:
!B (21Hex & 42Hex)
Reply: ACK = The DK910 displays the gross weight.
NAK = The DK910 cannot switch over.
DK900 7